ANNULOSA: INSECTA. 265 



The Diptera constitute one of the largest of the orders of 

 the Insecta; the House-flies and Flesh-flies (Musca), Gnats 

 '(Cu/ex), Forest-flies (Hippobosca), Crane-flies {TipuUda), and 

 Gad-flies (Tabanidce), constituting good examples. 



Fig. 92. — Diptera. Crane-fly. ( 7>^»/a ^i^rocni}. 



Order IX. Lepidoptera. — Mouth suctorial, consisting of 

 a spiral trunk or " antlia," composed of the greatly-elongated 

 maxillae, and protected, when not in use, by the cushion-shaped 

 hairy labial palpi. Maxillae forming two sub-cylindrical tubes, 

 united together by inosculating hooks, and constituting an in- 

 termediate tube by their junction. Maxillary palpi minute; 

 labrum and mandibles rudimentary. Head, thorax, and ab- 

 domen more or less covered with hair. Wings, four in num- 

 ber, covered with modified hairs or scales ; wanting in the 

 females of a few species. Nervures not very numerous, mostly 

 longitudinal. Antennse almost always distinct, and composed 

 of numerous minute joints. 



This well-known and most beautiful of all the orders of 

 Insects comprises the Butterflies (fig. 93) and the Moths (fig. 

 94) ; the former being diurnal in their habits, the latter mostly 

 crepuscular or nocturnal. 

 . The larvae of Lepidoptera (fig. 94), commonly called " cater- 

 pillars," are vermiform in shape, normally composed of thirteen 

 segments, the anterior portion forming g. distinct homy head, 



